Abstract
Excitations of free electrons and optical phonons are known to permit access to the negative real part of relative permittivities (μ′<0) that yield strong light-matter interactions. However, negative μ′ arising from excitons has been much less explored. Via development of a dielectric-coating based technique described herein, we report fundamental optical properties of two-dimensional hybrid perovskites (2DHPs), composed of alternating layers of inorganic and organic sublattices. Low members of 2DHPs (N=1 and N=2) exhibit negative μ′ stemming from the large exciton binding energy and sizable oscillator strength. Furthermore, hyperbolic dispersion (i.e., μ′ changes sign with directions) occurs in the visible range, which has been previously achieved only with artificial metamaterials. Such naturally occurring, exotic dispersion stems from the extremely anisotropic excitonic behaviors of 2DHPs, and can intrinsically support a large photonic density of states. We suggest that several other van der Waals solids may exhibit similar behaviors arising from excitonic response.
| Original language | English |
|---|---|
| Article number | 127401 |
| Journal | Physical Review Letters |
| Volume | 121 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Sep 19 2018 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
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Hyperbolic Dispersion Arising from Anisotropic Excitons in Two-Dimensional Perovskites. / Guo, Peijun; Huang, Wei; Stoumpos, Constantinos C.; Mao, Lingling; Gong, Jue; Zeng, Li; Diroll, Benjamin T.; Xia, Yi; Ma, Xuedan; Gosztola, David J.; Xu, Tao; Ketterson, John B.; Bedzyk, Michael J.; Facchetti, Antonio; Marks, Tobin J; Kanatzidis, Mercouri G; Schaller, Richard D.
In: Physical Review Letters, Vol. 121, No. 12, 127401, 19.09.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Hyperbolic Dispersion Arising from Anisotropic Excitons in Two-Dimensional Perovskites
AU - Guo, Peijun
AU - Huang, Wei
AU - Stoumpos, Constantinos C.
AU - Mao, Lingling
AU - Gong, Jue
AU - Zeng, Li
AU - Diroll, Benjamin T.
AU - Xia, Yi
AU - Ma, Xuedan
AU - Gosztola, David J.
AU - Xu, Tao
AU - Ketterson, John B.
AU - Bedzyk, Michael J.
AU - Facchetti, Antonio
AU - Marks, Tobin J
AU - Kanatzidis, Mercouri G
AU - Schaller, Richard D
PY - 2018/9/19
Y1 - 2018/9/19
N2 - Excitations of free electrons and optical phonons are known to permit access to the negative real part of relative permittivities (μ′<0) that yield strong light-matter interactions. However, negative μ′ arising from excitons has been much less explored. Via development of a dielectric-coating based technique described herein, we report fundamental optical properties of two-dimensional hybrid perovskites (2DHPs), composed of alternating layers of inorganic and organic sublattices. Low members of 2DHPs (N=1 and N=2) exhibit negative μ′ stemming from the large exciton binding energy and sizable oscillator strength. Furthermore, hyperbolic dispersion (i.e., μ′ changes sign with directions) occurs in the visible range, which has been previously achieved only with artificial metamaterials. Such naturally occurring, exotic dispersion stems from the extremely anisotropic excitonic behaviors of 2DHPs, and can intrinsically support a large photonic density of states. We suggest that several other van der Waals solids may exhibit similar behaviors arising from excitonic response.
AB - Excitations of free electrons and optical phonons are known to permit access to the negative real part of relative permittivities (μ′<0) that yield strong light-matter interactions. However, negative μ′ arising from excitons has been much less explored. Via development of a dielectric-coating based technique described herein, we report fundamental optical properties of two-dimensional hybrid perovskites (2DHPs), composed of alternating layers of inorganic and organic sublattices. Low members of 2DHPs (N=1 and N=2) exhibit negative μ′ stemming from the large exciton binding energy and sizable oscillator strength. Furthermore, hyperbolic dispersion (i.e., μ′ changes sign with directions) occurs in the visible range, which has been previously achieved only with artificial metamaterials. Such naturally occurring, exotic dispersion stems from the extremely anisotropic excitonic behaviors of 2DHPs, and can intrinsically support a large photonic density of states. We suggest that several other van der Waals solids may exhibit similar behaviors arising from excitonic response.
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U2 - 10.1103/PhysRevLett.121.127401
DO - 10.1103/PhysRevLett.121.127401
M3 - Article
VL - 121
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 12
M1 - 127401
ER -